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ace customs 
Member - Posts: 25
Member spacespace
Joined: September 15, 2004
Location: United States
Posted: April 17, 2005 at 11:29 PM / IP Logged  

Is there another way to hook the batteries up so that I dont have to use an isolator.  And does it matter if the battery in the trunk is smaller than the underhood. I noticed that in some previous post that was mentioned. Dry or Wet also.

Ace Customs
haemphyst 
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Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: April 18, 2005 at 12:15 AM / IP Logged  
NEVER use different capacity batteries, UNLESS they are isolated, and even then, this is not the optimal situation. Also, make certain your batteries are close to the same age, meaning buy them both at the same or close to the same time...
As far as hooking them up? Alternator output to positive of front battery, to positive of back battery, ground both to the chassis... make SURE you use good, heavy wire, and it will be absolutely critical that you get a good ground point... no SEAT BOLTS, please!
Battery type means NOTHING, as long as they are the same type, front and rear...
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
ace customs 
Member - Posts: 25
Member spacespace
Joined: September 15, 2004
Location: United States
Posted: April 18, 2005 at 11:28 AM / IP Logged  

k thanks. You didnt say, but it sounds like I dont have to use an isolator as long as they are the same size is the true?

Ace Customs
haemphyst 
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Platinum spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: April 18, 2005 at 12:56 PM / IP Logged  
Correct. I have never recommended isolators, (I usually recommend strongly AGAINST isolators) as long as the batteries are the same type, age, and capacity. there is no problem with running them in direct parallel, as long as these conditions are all met...
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
wayland1985 
Silver - Posts: 353
Silver spacespace
Joined: December 31, 2003
Location: United States
Posted: April 18, 2005 at 6:01 PM / IP Logged  
I'm thinking save yourself a headache further down the road. Go to a shop, and buy a new H/O Alternator. A second battery is going to take up more space, and add more of a load to your alternator.
Right now you have a pretty potent system from the sounds of it. If 3 farads are draining as quickly as you say they are, then you should definately look into an Alternator. Whether or not you upgrade to 2400 watts RMS.
The only reason I see fit for adding a second battery is only for parked play. That is, you should only have additional batteries if you are playing your radio with the engine off. Even then, you'll need a H/O alternator...
Besides, why add the extra weight of an additional battery to a sporty car like the X-type???
~wayland
ace customs 
Member - Posts: 25
Member spacespace
Joined: September 15, 2004
Location: United States
Posted: April 18, 2005 at 10:49 PM / IP Logged  
thanks for the help but, one last question. What does everyone think about high power capacitors. I mean like 30 farad. Will they run down faster than a battery.
Ace Customs
Poormanq45 
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Joined: October 27, 2004
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Posted: April 18, 2005 at 11:22 PM / IP Logged  
someone wrote:
I'm suprised you only have 4 guage w/ all that power... 4guage is really only good till around 800 rms then you need to move up to 1/0
kev
supradude wrote:
You need bigger wire, 2 gage or even better than that 0 gage. Also a HO alternator. The caps are a waste in my opinion. Also upgrade the BIG 3 will help.
Inccorect. 4 guage wire is good for either 60 or 80 amps at 240volts!
This translates roughly into 1600amps at 12volts. 1600x12 = 19200watts.
I don't quite understand why people in car audio can't understand this concept.
Is it because of the FnF crap that peopel think that Bigger is Better?
Oh, what's even funnier is that the wire used inside the box is usually only 12guage.
So tell me, if it's mandatory that you use such a high guage wire, then wire is it that you use such "small" wire to actually connect the amp to the driver?
I understand that wire coming from th ebattery to the amp has to travel ~15ft, but this is an extremely short distance.
4gueage wire is good for a few thousand ft while still retaining the ability to transfer 50amp+ safely.
sedate 
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Joined: July 03, 2004
Location: Colorado, United States
Posted: April 18, 2005 at 11:59 PM / IP Logged  
*Ace* You poor poor man. You do not seem really understand what you are trying to do here.... and judging by this topic so far... neither does anyone else...
Next time you post a question, how about being a wee bit more specific about your power setup?
I *think* you trying to:
Externally bridge two Orion 1200D amps to a single H2 subwoofer.. and now you want to do it *twice.*
While I fancy myself a car-stereo expert, as DYohn and heamphyst (hemp-fist? what does that mean anyway?) will attest, I'm far from, and I really have no clue how those amps "externally bridge" themselves so I'm just going to assume that you are running the 1-ohm load from each amp, for a full 1200 watts to each voice coil of a DVC 2-ohm H2. (again, I have absolutely no idea how "externally bridging" something works or what the wiring looks like, but given the behavior you describe I think I'm prolly right..)
So as it stands, you are asking a round 2400 watts from your amps.. and that is *output* nevermind the extra 30% or so in amplifier efficency you are going to lose. So lets assume you are asking about 3000 watts from your power system, all 3 caps, and all. By the way, the capacitors, despite what most ppl on this board will tell you, are not at all useless.. but when you are as power deficient as you are..they might as well be...
Plugging this into Ohms law we get amps=watts/volts....
or 240 = 3000/12.5
Jag or not *no* OEM alt makes anywhere near 240 amps. Not only does *no* OEM alt make anything near that *no* OEM battery will take that kind of draw for long...
Batteries are kinda strange things.. car batteries especially... you probably fried you battery almost immediately with those amps... yet... you still could get 12.5 - 14.4 V out of it.. enough to start it and roll the nice windows down...but under any load what-so-ever the thing immediately gives out.. which is why your caps are good for *one or two thumps* I'd put 10-1 your battery is bad, whether or not it starts your car..
If you are not going to consider a HO alt, here is the *reality* of your situation:
1) Scrap the idea of new amps. Not only is that a stupid waste of money, you will never ever ever get any use out of them as your power draw will now jump to something on the order of 400 - amps and that is hard for even the beefiest of batteries and all the capacitors you care to shake a stick at to keep up with. 400-amps, my friend, will run an electric chair that woulda put Mickey Rourke down *the first time* (...anyone?)
2)4-gauge is totally under-rated for what you want. You shouldn't have a scrap of power wire in your entire system, regardless of your battery, alt, or cap setup, less than 2-gauge running around at all. Lots and lots of 2-gauge. (Or 0/1 (or is it 1/0?) gauge, I think 2-gauge is rated to like 220-amps) The *only* 4-gauge in your system should be running off of the distro block straight to your amps. Each is grounded with 4-gauge as well.
3)For the amps you already have, let alone the ones you should not add, you need *at least* a pair of deep cycles in parallel. You need to wire these to a 200-amp RELAY. When ever you turn the key to "ACC" these batteries connect in PARALLEL, when you turn the car off, they disconnect. If you can afford an X-type, I dunno why you couldn't afford two Yellow Tops. Buy two of whatever fits under your hood.
4)Even if I'm totally wrong, and you only need half that much power from your amps, you still are asking *quite* a load. 120 - 150 amps is a tremendous drain on a stock charging system... again, Jag or not. The 'two batteries' suggestion should still be applied.
5)As power deficient as you are, all the capacitors in the world are not going to help... you need *massive* storage capacity, not voltage stiffening...
240 amps is sick man.
Sick.
"I'm finished!" - Daniel Plainview
sedate 
Silver - Posts: 1,173
Silver spacespace
Joined: July 03, 2004
Location: Colorado, United States
Posted: April 19, 2005 at 12:14 AM / IP Logged  
Whoa Poormanq45:
"4gueage wire is good for a few thousand ft while still retaining the ability to transfer 50amp+ safely."
What does 50 amps matter when he's trying to run two 1200 watt amps? His pull is like 5 or 6 times that.
For that matter, what about the 100s of tables that look *exactly* like this one?
"Oh, what's even funnier is that the wire used inside the box is usually only 12guage. "
And that is because ppl are *supposed* to use 12 gauge or is that just what ppl use? Every decent amp I've ever seen has terminals that accept 8 gauge speaker wire.. as is what *should* be used.
"I'm finished!" - Daniel Plainview
haemphyst 
Platinum - Posts: 5,054
Platinum spaceThis member has been recognized as an authority in Electrical Theory. Click here for more info.spaceThis member has been recognized as an authority in Mobile Audio and Video. Click here for more info.spacespace
Joined: January 19, 2003
Location: Michigan, Bouvet Island
Posted: April 19, 2005 at 1:11 AM / IP Logged  
someone wrote:
I'm suprised you only have 4 guage w/ all that power... 4guage is really only good till around 800 rms then you need to move up to 1/0
Actually, you are wrong. A #4 cable will safely carry 150A up to around 16 feet. The distance notwithstanding, let's do the math, shall we?
150A * 14.4v = 2160w (IN) 2160w (in) * .6 (assuming 60% efficiency - a conservative esitmate) = 1296w OUT
A single 4 gauge wire will handle a 1200 watt amplifier all day.
Poormanq45 wrote:
supradude wrote:
You need bigger wire, 2 gage or even better than that 0 gage. Also a HO alternator. The caps are a waste in my opinion. Also upgrade the BIG 3 will help.
Inccorect. 4 guage wire is good for either 60 or 80 amps at 240volts!
This translates roughly into 1600amps at 12volts. 1600x12 = 19200watts.
I don't quite understand why people in car audio can't understand this concept.
Please see the above notice I just typed. I think if YOU want to run 1600A through a #4, I don't want you ANYWHERE near my house or car wiring... A wire is NOT a transformer. A #4 cable is SAFE at no more than 150A, whether it is carrying 12 or 12000 volts. It is true, he needs bigger wire, considering the current capacity he is trying to apply, but the math remains the same.
Poormanq45 wrote:
Is it because of the FnF crap that peopel think that Bigger is Better?
Oh, what's even funnier is that the wire used inside the box is usually only 12guage.
So tell me, if it's mandatory that you use such a high guage wire, then wire is it that you use such "small" wire to actually connect the amp to the driver?
I understand that wire coming from th ebattery to the amp has to travel ~15ft, but this is an extremely short distance.
4gueage wire is good for a few thousand ft while still retaining the ability to transfer 50amp+ safely.
Speaking of somebody who really does not understand...
An amplifier output is a high VOLTAGE output, this means you can use a smaller gauge wire, and still observe acceptable losses. When you raise the voltage, Ohm's law says you MUST lower the current, if you are maintaining the same amount of POWER. If you ONLY raised the voltage, without lowering the current you would be increasing the power... Something that cannot be done. This would be equivalent to negative losses. What I mean by this is (and let's assume a 100% efficient amplifier) If you have a 100A drain at 12v, this is 1200w, right? Well across 4 ohms, 12 volts is only 36 watts, a FAR cry from 1200... to get 1200 watts OUT, you must raise the voltage to 69 volts. If we were to raise the voltage to 69 volts, but KEEP the current at 100A, our (only) 100 percent efficient amplifier would be outputting 6900w into a 4 ohm load - it can't happen, it would be a 690% efficient amplifier... As Ohm's law says, the current MUST go down, if the voltage goes up. In this case, down to 17.4A, perfectly capable of being passed through a #12 speaker wire safely...
sedate wrote:
*Ace* You poor poor man. You do not seem really understand what you are trying to do here.... and judging by this topic so far... neither does anyone else...
Next time you post a question, how about being a wee bit more specific about your power setup?
I *think* you trying to:
Externally bridge two Orion 1200D amps to a single H2 subwoofer.. and now you want to do it *twice.*
While I fancy myself a car-stereo expert, as DYohn and heamphyst (hemp-fist? what does that mean anyway?) will attest, I'm far from, and I really have no clue how those amps "externally bridge" themselves so I'm just going to assume that you are running the 1-ohm load from each amp, for a full 1200 watts to each voice coil of a DVC 2-ohm H2. (again, I have absolutely no idea how "externally bridging" something works or what the wiring looks like, but given the behavior you describe I think I'm prolly right..)
So as it stands, you are asking a round 2400 watts from your amps.. and that is *output* nevermind the extra 30% or so in amplifier efficency you are going to lose. So lets assume you are asking about 3000 watts from your power system, all 3 caps, and all. By the way, the capacitors, despite what most ppl on this board will tell you, are not at all useless.. but when you are as power deficient as you are..they might as well be...
Plugging this into Ohms law we get amps=watts/volts....
or 240 = 3000/12.5
That's "Mr. haemphyst" to you... LOL It's an "olde English" spelling twist for ham-fist (or the art of being ham-fisted, see ham-handed at dictionary.com, definition three), because sometimes I don't know my own strength, and I am always accused of over tightening connectors, bolts, screws, etc.
sedate wrote:
Jag or not *no* OEM alt makes anywhere near 240 amps. Not only does *no* OEM alt make anything near that *no* OEM battery will take that kind of draw for long...
Batteries are kinda strange things.. car batteries especially... you probably fried you battery almost immediately with those amps... yet... you still could get 12.5 - 14.4 V out of it.. enough to start it and roll the nice windows down...but under any load what-so-ever the thing immediately gives out.. which is why your caps are good for *one or two thumps* I'd put 10-1 your battery is bad, whether or not it starts your car..
If you are not going to consider a HO alt, here is the *reality* of your situation:
1) Scrap the idea of new amps. Not only is that a stupid waste of money, you will never ever ever get any use out of them as your power draw will now jump to something on the order of 400 - amps and that is hard for even the beefiest of batteries and all the capacitors you care to shake a stick at to keep up with. 400-amps, my friend, will run an electric chair that woulda put Mickey Rourke down *the first time* (...anyone?)
2)4-gauge is totally under-rated for what you want. You shouldn't have a scrap of power wire in your entire system, regardless of your battery, alt, or cap setup, less than 2-gauge running around at all. Lots and lots of 2-gauge. (Or 0/1 (or is it 1/0?) gauge, I think 2-gauge is rated to like 220-amps) The *only* 4-gauge in your system should be running off of the distro block straight to your amps. Each is grounded with 4-gauge as well.
3)For the amps you already have, let alone the ones you should not add, you need *at least* a pair of deep cycles in parallel. You need to wire these to a 200-amp RELAY. When ever you turn the key to "ACC" these batteries connect in PARALLEL, when you turn the car off, they disconnect. If you can afford an X-type, I dunno why you couldn't afford two Yellow Tops. Buy two of whatever fits under your hood.
4)Even if I'm totally wrong, and you only need half that much power from your amps, you still are asking *quite* a load. 120 - 150 amps is a tremendous drain on a stock charging system... again, Jag or not. The 'two batteries' suggestion should still be applied.
5)As power deficient as you are, all the capacitors in the world are not going to help... you need *massive* storage capacity, not voltage stiffening...
240 amps is sick man.
Sick.
All very good points... As it stands right now, he is FAR overtaxing his present electrical system, and to add MORE will only cause it's early demise... Let's see if he is interested in listening to some really good advice...
It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."
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